Water treatment staff were seen arriving at the Bibby Stockholm in Portland on August 14 after legionella bacteria was discovered on the vessel.

Specialist water treatment firm Offshore Water Management (OWM) were spotted arriving at the barge.

Migrants were removed from the barge on August 11 after legionella bacteria was discovered on the ship.

The council has said it informed the “responsible organisations” - barge operators CTM and Landry & Kling - about the preliminary test results on August 7, the same day it received them.

However, the government denies this claiming the Home Office only received a written notification on August 9.

Home Office contractors were told about traces of Legionella bacteria found on the Bibby Stockholm on the same day asylum seekers were transferred on to the barge, Dorset Council has said.

A Specialist water treatment firm, Offshore Water Management from Scotland were spotted arriving at the Bibby Stockholm in Portland Port, this morning.

The discovery eventually led to the removal of all 39 people who had moved onto the barge on Friday 11 August.

The council has now said it informed the “responsible organisations” - barge operators CTM and Landry & Kling - about the preliminary test results on Monday 7 August, the same day it received them.